code: def calculate_area(box: Union[List[int], np.ndarray]) -> float:
      """
      Args:
          box (List[int]): [x1, y1, x2, y2]
      """
      return (box[2] - box[0]) * (box[3] - box[1])
  
imports: from collections.abc import Sequence
  from typing import List, Union
  import numpy
  import torch
  from sahi.annotation import BoundingBox, Category, Mask
  from sahi.prediction import ObjectPrediction
label_desc: Use image node_id 4 for calling a global function with example usage: calculate_area(box) and returns: unknown